A variety of sealing devices have heretofore been used or proposed for use for sealing bearings of the type comprising a pair of annular race members incorporating a plurality of anti-friction elements such as balls in the raceways thereof to retain lubricant within the bearing and to prevent entry of dirt, water and other extraneous materials into the interior of the bearing. In ball bearing assemblies of the type employed in the wheels of automobiles, the severe service conditions necessitate particularly effective sealing devices to exclude the entry of dirt, water, sand and salt which otherwise might materially reduce the useful operating life of such bearings. It is desirable in wheel bearing assemblies and other bearing assemblies subjected to similar severe operating conditions to provide multiple lip seal assemblies to increase the sealing characteristics and exclusion of undesired extraneous matter.
A continuing problem associated with wheel bearing assemblies, especially ball bearings, and the like has been the lack of sufficient axial clearance between the anti-friction elements and the side edges of the annular race members to accomodate multiple lip sealing devices of the types heretofore known. Because of this, it has been necessary in such instances to employ single-lip seals which provide less than optimum sealing characteristics. A further problem has been in the tendency of the sealing lips of the sealing device to become oriented in a reverse axial direction during installation of the sealing device in the bearing assembly, further detracting from the sealing characteristics thereof. The magnitude of deflection of the annular sealing members in multiple lip sealing devices of the types heretofore known has also been extremely great, causing excessive pressure on the sealing surface, promoting drag and wear of the sealing device with an attendant reduction in its useful operating life.
The problems and disadvantages associated with prior art sealing devices is overcome in accordance with the present invention in which a double-lip seal is provided of compact axial width, enabling its use in bearing assemblies which normally can accomodate only a single-lip seal and wherein the individual sealing lips are contoured and project at an acute angle in the axial direction of their ultimate assembled position, assuring proper orientation thereof during installation and reducing friction and drag of the sealing lips on the bearing surfaces against which they are disposed in resilient sliding contact.